Adjustable-pitch propeller for airplanes



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S. W. CARTER ADJUSTABLE PITCH PROPELLER FOR AIRPLANES Filed Aug. 13, 1921 3 Sheets-Sheet B I To all 'whomit may conaem:

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UNITED STATES 1,455,990 PATENT orries.

EL W. CARTER, OF WASHINGTON, DISTR ICI OF COLUMBIA.

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Application filed August 13, 1921. Serial 1T0. 492,040.

Be it known that SAMUEL W. CARTER, a citizen of the United States, residing at Washington, in the District of Columbia, has invented certain new and useful Improvements in Adjustable-Pitch Propellers for Airplanes, of which the following is a specification, reference being had therein to the accompanying drawing.

The invention relates to air propellers for airplanes and other lighter-than-airshi and has for its object to provide a propel 'er of this character wherein the propeller blades may be simultaneously moved for varying the pitch, so as to give equal propulsion and efficiency in the atmospheric changes of altitudes. Also to provide means whereby the pivoted propeller blades may be simultaneously set at a neutral angle while the plane is. gliding for purposes of landing, or for testing the motor before starting a flight.

A further object is to provide an adjustable pitch propeller comptrising a frame carried by a propeller sha sleeves rotatably mounted in bearings at the ends of said frame, the inner ends of said sleeves bein provided with (gears, with which gears racl i bars mesh, sai rack bars are carried by a 80 longitudinally movable yoke slidably mounted on the drive shaft and rotatable therewith. Also to provide worms located adjacent each side of the drive shaft and mounted in brackets, said worms having threaded thereon a movable yoke controlling memher, and means whereby when one of said worms is rotated, the other worm will simultaneously rotate.

A further object is to provide means whereby -the butts of the propeller blades will be positively held in the rotatable sleeves carried by the frame, said means comprising oppositely disposed wedge shaped blocks extending. through rectangular shaped apertures in the opposite sides of the sleeves, said blocks being provided with integral flanges conforming to the outer periphery of the sleeves, and to provide bolt means connecting the oppositely disposed blocks together for positively holding the propeller blades against displacement incident to centrifugal force.

With the above and other objects in view the invention resides in the combination peller supporting forth, shown in the drawings, described and claimed, it being understood that changes in the precise embodiment of the invention :may be made within the scope of what is claimed without departing from the spirit of theinvention.

In the drawings Figure 1 is a side elevation of the adjust-.

able propeller, showing the operating mechanism and the drive shaft. v

Figure 2 is a vertical sectional view taken on line 2- 2 of Figure 1. I

Figure 3 is a vertical sectional view taken on line 3-3 of Figure 1.'

Figure 4 is a horizontal sectional view taken on line 44 of Figure 1.

Figure 5 is a vertical sectional view the yoke.

Figure 6 is a vertical sec.t1onal view taken on line 6-6 of Figure 1.

Figure 7 is'a perspective view of the butt end of one of the propeller blades.

Figure 8 is a perspective view of one of the propeller butt, sleeves.

.in any suitable manner, and 2 a flanged sleeve secured on the rectangular shaped portion 3 of the shaft by means of a key 4. Engaging the outer faces of the flanges 5 of i the flanged sleeve 2 are the lugs 6 of bars 7, which bars are equidistant from each other and are held in place by means of bolts 8, which pass through the flanges 5, lugs 6, and plates 9, which engage the outer faces of the lugs 6, therefore it will be seen that a proframe 10 is provided, which frame is securely held on the rectangular shaped portion 3 of the drive shaft 1 and is held against rearward movement thereon by means of the nut 11 threaded on through the slidable collar for controlling the outer end of the shaft 1. The bars 7 are preferably formed from angle iron as shown in Figure 1, andhave secured thereto by meansof 'bolts 12 roller bearing collars, 13, in which collars roller bearings 14 are disposed, which roller: bearings engage the shoulders 15 of cylindrical propeller holding sleeves 16 and support the same in an antifrictional bearing in such a manner that the sleeve will be held against longitudinal moveagainst centrifugal force durin the rapid rotation'of the propeller as a w ole, and atthe same time so supporting the cylindrical sleeve that it may be easi1 rotated by operating mechanism hereina ter set forth for varying the pitch of the propeller blades. The roller bearing collars 13 are formed from segmentally shaped sections 17, which sections are bolted at 18 at diametrically opposite points thereby allowing the bearing to be disassembled for cleaning and repairing without disassembling the whole bearing collar or the entire propeller blade'holding structure. Adjacent the outer end 'of the frame 10 roller bearing collars 19 are secured by means of bolts 20, said collars being similarly constructed as the collars 13 and have disposed in annular raceways 21, roller bearings 22, which roller bearings also engage in the raceways 23 in the outer periphery of the butt receiving sleeves 16. It will be seen that the butt receiving sleeves 16 are anti-frictionally supported and supported in such a manner, and at-spaced points that they will freely move during a pitch changing operation, and also in such a manner that the sleeves in which the propeller butts 24 are secured will be held against displace ment incident to centrifugal force during the rotation of the propeller as a whole. The

butts 24 of the propellers 25 are inserted in the sleeves 16 under heavy pressure prefer ably by hydraulic press, and after thebutts 24 are in place in sleeves 16, a tool is inserted through the rectangular shaped 0 enings 26 which are diametrically dispose in the sleeves 16, and the butts 24 are provided with rectangular shaped recesses 27 corresponding in size to the rectangular shaped openings 26 in the sleeves 16. The recesses 27 are deeper at their sides adjacent the endof the butt 24 than at their outer sides an are provided with inclined outwardly I extending inner walls 28, and into which recesses 27 rectangular shaped blocks 28 are placed said blocks having their inner ends 29 wid forming tapering surfaces 31 which taper at the same angle as the inner faces 28 of the recesses 27 and form means disposed at a right angle to the propeller butts for holding said butts-against outward movement incident to centrifugal force during the ro-- tation of the propeller. The rectangular shaped blocks 28 are so shaped that a maximum amount of service engages in the recesses 27 of the but-ts 24 for holding the butts against outward movement, and that by reducing the width of the upper ends of the blocks 28 the amount of'material removed er than their outer ends 30, thereby a teases.

from the butts will be reduced, thereby preventing weakening of the butts. Each block.

28" is provided withintegral flanges 32 which 28 after the blocks have been forced into the recesses-27 'by means of bolts 33 which pass through the butts, preferably at right angle'positions to each other as shown and through the blocks 28. It will be seen that the blocks are securely held in place by the bolts 33'and that'theibutts are positively .held in such a manner that they will be held against outward movement during the 'rapid rotation of the propeller as a whole, at .which time the propeller blades are subjected to great centrifugal force.

engage the outer periphery of the sleeves 16 a and prevent .inward movementof the blocks The innerends of the sleeves 16 are pro--,

vided with gears 34 and with which gears the racks 35 located on opposite sides of the" shaft 1 mesh. The racks 35 are carried by a yoke 36, which yoke is longitudinally slidable on a rectangular shaped portion 3 of the shaft 1, and is provided with a. boss 37 which is secured a flange 38. Interposed between the flange 38, and the face 39 of the yoke 36 is a thrust. collar 40, which thrust collar is mounted on roller bearings 41 interposed between its inner periphery and the outer periphery of the boss 37, said thrust collar also having interposed between its sides and the flange 38 and face 39 and yoke 36 ball bearings 42, which ball bearings prevent, in connection with the roller bear ings 41, destruction of thethrust collar 40" incident to the rapid rotation of the yoke 36, which revolves with-the propeller as a whole.

It will be seen that the rack bars 35 engage l the ears.34 at opposite sides, therefore the bla es will .during a movement of the rack bars be rocked in their bearings in opposite directions thereby changing the pitch of the propeller blades as desired. Disposed at opposite sides of the drive shaft 1 arebrackets 43, which may be supported in any suitable manner on the fuselage, and rotatably mounted in bearings of said brackets are 'worms 44, which 'worms extend. through threaded bosses 45 of a thrust collar moving yoke 46, which yoke is provided with arms 47 which receives lugs 48-at diametrically opposite sides of the collar 40. The worms 44 are provided with sprockets 49, and around sald sprockets, a sprocket chain 50 extends. It will be seen that when the op'-;-

crating-shaft 51', which isuniversally connected at 52 to one of the worms 44, is ro- ,V-

tated that both worms 44 will simultaneously rotate thereby moving the yoke 46 and bosses 45 in such a niannixthat the rack bars 35 willbe reciprocated for changing the pitch of the propeller blades 25. The operating shaft may lead to the cockpit of the airplane and be rotatedin any suitable The invention having been set forth what is claimed as new and useful is 1. The combination with a. bearing sleeve disposed on the butt of a propeller blade, of means -for securing said sleeve on said butt, said means comprising oppositely disposed blocks extending through openings in the sleeve and into registering recesses in the butt, marginal flanges carried by the blocks and engaging the sleeve for limiting the inward movement of the-blocks, and bolts extending through the butt and connecting together the oppositely disposed blocks.

, 2. 'The combination with a bearing sleeve disposed on the butt of a ropeller blade, of

means for securing said s eeve on said butt,

said means comprising oppositely disposed rectangular shaped blocks extending through prising oppositely disposed rectangular shaped blocks extending through openings in the sleeve and into recesses in the butt, said rectangular shaped blocks being wider at their ends adjacent the inner end of the butt than at their outer ends, thereby presenting a maximum holding surface against displacement under centrifugal force, bolts extending through oppositely disposed 4 blocks for holding the same in close engagement with the sleeve and in the butt recesses and integral flanges carried by the blocks engaging the outer periphery". of the sleeve for limiting the inward movement of the block.

4. The combination with a bearing sleeve disposed'on the butt of a propeller blade, of means for securing said sleeve on said butt, said means comprising oppositely disposed rectangular shaped blocks extending through oppositely disposed rectangular shaped openings in the sleeve and into registering recesses in the butt, flanges carried by the outer ends of said blocks and engaging the outer periphery of the sleeve and a bolt passing through said oppositely disposed blocks for holding the same inthe openings and recesses.

In testimony whereof I hereunto aflix my signature.

SAMUEL w. CARTER. 

